There are two reasons for that. First, Sabathia's deal comes with an opt-out clause in which the hurler can forego the final four years of his contract and re-enter the market. While the fine print of his deal hasn't been reported, and while many view the presence of the clause as an unmitigated negative for the Yankees, the terms on both sides of that option suggest a flat pay rate of $23 million per year, arguably telegraphing the pitcher's intention to walk away, since the bet is that he'll increase his annual value over the course of that three-year stretch and face a more favorable economic climate than the current recession. Burnett's deal contains no such clause, though ironically he became a free agent by exercising an opt-out clause in his five-year, $55 million deal with the Blue Jays. The Yankees are on the hook for all five years of his new deal unless they trade him.

Second, and more relevant performance-wise, Sabathia has proven himself to be a durable workhorse during his eight big-league seasons, reaching the level of 30 starts seven times, never throwing less than 180 1/3 innings, and making only one trip to the disabled list, that due to a groin strain in 2006. Burnett, on the other hand, has reached 30 starts just twice in 10 seasons-both times prior to entering the market as a free agent-and has topped 180 innings just three times. He's got a long history of arm problems, one that includes Tommy John surgery in 2003 and more than four months on the DL in 2006 and 2007, the former for elbow pain caused by the breakup of scar tissue from his TJ, and the latter for a shoulder strain. Both times, he came off the DL for less than a week before returning, furthering the perception that he was unwilling to pitch through any discomfort. Burnett "has often needed reassurance that he's healthy," wrote BP injury analystWill Carroll amid the pitcher's 2006 elbow woes.

Burnett's combination of fragility and perceived squeamishness calls to mind the darkest chapter of Yankee GM Brian Cashman's tenure, the two deals he inked at the 2004 Winter Meetings with a pair of injury-riddled pitchers coming off rare healthy, effective seasons, Carl Pavano and Jaret Wright. The Yankees just cleared the former's four-year, $39.95 million deal from the books this fall. A teammate of Burnett's with the Marlins from 2002 through 2004, Pavano signed with the Yankees in December 2004 after a season in which he'd gone 18-8 with a 3.00 ERA in 222 1/3 innings-figures that were all career bests, but representing just the second time the pitcher had been healthy and effective over a full season. Pavano made just 19 starts in his four years in the Bronx, and his litany of injuries reached such an absurd level that his initials came to stand for "Can't Pitch." Wright was coming off his first healthy and effective season since 1998; he managed just 43 starts over the next three years (the last one in Baltimore) and was rarely effective. Suffice it to say that the Yankees' recent record of banking on pitchers with sketchy track records isn't a good one.

To be fair, Burnett is a good pitcher when healthy. Though he had never won more than 12 games prior to the 2008 season, that was a function of his lack of availability and the occasionally meager offensive support he had received, and his ERAs have been 13 percent better than the park-adjusted league average over the past four years, which ranks 16th among pitchers with at least 700 innings in that span. His 4.07 ERA this past year was inflated by about half a run thanks to his .318 BABIP, 18 points above league average.

Burnett's strikeout rate over those four years, 8.9 per nine innings, is even better, ranking third among that group behind Cy Young winners Jake Peavy and Johan Santana. As noted in discussing Sabathia, strikeout rate is the key indicator of a pitcher's future success because it provides the window into his ability to fool hitters with his offerings. A pitcher's strikeout rate generally declines as he ages, but a high strikeout rate gives him more headroom before he does so. To the extent that the Yankees must look five years into the future on Burnett's deal, his strikeout rate offers some assurance of future effectiveness-if not availability.

Furthermore, strikeouts decrease a pitcher's reliance on his defense, and since the Yankees were one of the majors' least efficient teams in the field, ranking 25th out of 30 teams in raw Defensive Efficiency (.682), they've done well for themselves this week: Burnett's 231 strikeouts led the American League and ranked only behind Sabathia's 251 (compiled across both leagues) and Tim Lincecum's 265. Once upon a time, the Yankee staff ranked among the league's strikeout leaders. From 1998 through 2003, when they won five pennants and three World Championships, they were never lower than third in the AL in that category. Since then, they've cracked the top three just once, and haven't won a single pennant:

Surprisingly, they did finish in the top three in strikeout rate in 2008, despite a revolving-door staff that saw 13 pitchers make at least one start, and endured season-ending injuries to Chien-Ming Wang and Joba Chamberlain. With staff strikeout leader Mike Mussina retiring and second-ranked Andy Pettitte unsigned, the Yankees clearly needed to find other high-strikeout pitchers to replace them. Particularly so, given that their defensively inferior keystone combination of Derek Jeter and Robinson Cano appears set in stone for the foreseeable future.

The signing leaves the Yankees committed to four starters: Sabathia, Burnett, Wang, and Chamberlain. Reports earlier this week suggested they remained interested in a one-year, $10 million deal for Pettitte, and might even be interested in a multi-year deal with free agent Derek Lowe. While those may have been bluffs designed to accelerate Burnett's decision between offers from the Yankees and Braves, it's now clear that at most one rotation spot is available to Phil Hughes and Ian Kennedy, two of the three young hurlers (along with Chamberlain) around whom Yankee GM Brian Cashman structured the rotation last winter after bypassing a potential trade for Johan Santana.

That pair didn't win a single game between them in 2008 while combining for a 7.45 ERA in 17 starts and dealing with injuries, and because of that, both pitchers' stock has fallen considerably. Regarding the former, once considered among the game's top pitching prospects, Baseball Prospectus' John Perrottoobserved from this week's meetings that the Yankees seem "willing to trade Phil Hughes, who other teams are starting to see as really nothing more than a No. 3 or No. 4 starter." If he's not traded, Kennedy may be; his name was said to surface in discussions for Brewers center fielder Mike Cameron last month.

With Burnett even more than Sabathia, the Yankees had best make sure they cultivate adequate rotation depth behind him. Now that he's not pitching for a contract, it might only be a matter of time before Burnett winds up on the trainer's table or the disabled list, rekindling uncomfortable memories of fragile free agents past.

Jay Jaffe is an author of Baseball Prospectus. Click here to see Jay's other articles.
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I've never forgetten Will reporting that Burnett felt like he had "sharks in his elbow" when he was working through a bout of post-DL tentativeness. I think that's why as a Yankees fan I should feel like such a dope being optimistic about this signing. But this signing is about upside, about another shot at blowing away the competition in the playoffs with a dominant pitching performance (The other shots at domination being Sabathia and Chamberlain). Cashman's next move will tell you whether they'll roll the dice on upside again - Sheets - or whether they value health and reliability more - Lowe or Pettitte. Pettitte has been very average for the last 3 years - to the point of being simply a familiar faced innings eater if he's brought back. He'd be a #3 for a lot of teams, but an adequate #5 for the Bombers.

Random question: if Jeter had stepped over to 3B when A-Rod arrived, allowing A-Rod to man SS, what benefit would defensive projections, by season, extrapolate to? That is, how many Earnies has Jeter cost the pitching staff over the years that might otherwise have been gobbled up by the superior performer that is and has always been A-Rod?

What's interesting to me is that Jeter's RAA is at -11 (heavily skewed by -18 in 2008) in the 4 years since A-Rod took over 3B. In the 4 years prior to A-Rod, Jeter's RAA was -82. So, using no analysis whatsoever, clearly A-Rod has saved the Yanks from yielding 71 runs in that span, or almost 18 runs a year. This is worth, what, roughly 4 wins anually?

Thanks to the accident of geography and resulting cash available from the local media market, the Yankees/Mets (and to a lesser extent, the Red Sox) operate on one level and everyone else operates on a lower level. Doesn't anyone think this is bad for baseball's competitive balance?

MLB is not the NFL where the teams have determined an equitable way to share broadcasting revenue. The NY Giants do not have a profoundly unfair financial advantage over the Green Bay Packers because they equally share boradcasting revenue that the NFL receives. Isn't that the way it should be?

Think about it -- the Yankees can schedule a homestand in the Bronx but they have no homestand unless Kansas City, Detroit and Cleveland visit Yankee Stadium to play. Why should revenue paid to broadcast the game itself only subsidize the efforts of one of the teams to put a roster together?

I've heard the argument that it's a free country and the Yankees should be able to spend their money any way they want. This argument, however, is specious because MLB is exempt from the nation's antitrust laws and, consequently, is not a free market.

What if Kansas City (or Tampa Bay or Minnesota) says "we can't compete with the media revenue stream in our market so we want to move -- to Northern New Jersey where we share the New York market with the Yanks and the Mets? The Yankees would naturally object, citing territorial control of the New York market. It seems that the Yankees are hyper-capitalists when that serves its purpose and, in the next minute, are hyper-socialists (i.e., no other team can move into their market) when that serves its purpose. What kind of financial advantage would the Yankees have if three or four or five teams played in New York? New York historically had three teams and, in a capitalist system, shouldn't the market determine how many teams New York can support?

It's an interesting question to think about what effect adding another team to the New York media market would have. My guess would be basically none over the short-term. The Yankees revenue stream is a function of the YES network, and as long as people want to watch Yankees games, their revenues won't decrease.

But, even assuming that the Yankees/Mets would allow the teams to move, it's not a given that the teams would choose to do so. The cost of a move is extremely large (including stadium construction) and public money is becoming less available.

Finally, it may be a mistake to assume that the first goal is to be competitive. Certainly the Twins are often competitive, but I would argue this is in spite of their owner, not because he has contributed in any way. Small market teams receive massive amounts of money in revenue sharing and choose not to reinvest it in the team (perhaps due to the double-marginal tax rate that the revenue sharing system has created), preferring to take it as profit. I don't think Carl Pohlad would like to move to NY and compete with the other franchises -- to get lots of revenue in a multi-team market, you need to spend money and win games, two things Pohlad is arguably not particularly interested in.

1. First, doesn't baseball's antitrust exemption prevent franchises from moving wherever they choose, unless they have approval from the league? Al Davis moved the Raiders from Oakland to L.A. and then back to Oakland but pro football is not exempt from antitrust regulation. The fact that owners and players in all the pro sports can agree in their collective bargaining agreement to items like the amateur draft (which absent a CBA would raise antitrust issues) is irrelevant to my point here.

2. Second, major league franchises are not precisely analagous to Subway franchises in a particular geographic area. Such Subway franchises operate independently of each other. Yes, Subway may keep a new franchisee from opening a restaurant next to door to an existing Subway but in terms of operation, they are independent of each other. Same cannot be said for the Yankees and the Royals.

The Yankees can schedule a homestand but they need an opponent to have a game. If the system for distributing local media revenue gives the Yankees the opportunity to spend $200 million/year for revenue but the Royals can only spend $40 million/year, then eventually the Royals will become nothing more than baseball's answer to the Washington Generals.

Actually, the small market teams like K.C., Milwaukee and Cincinnati have more power than they may realize in this situation. What would happen, for example, if the Royals and other small market clubs simply refused to play the Yankees? Without opponents, the Yankees have no games to play. The small market clubs need to play this card to make the Yankees act responsibly. The Yanks -- led by the petutlant, cry-baby Steinbrenner family -- certainly won't do it on their own.

Justice's comment is flawed in two ways -- he makes two mistakes that a lot of others also make.

Baseball is NOT really exempt from the nation's antitrust laws -- at least, not exempt to an extent greater than any other unionized industry. Anything agreed to in the course of collective bargaining is generally exempt from the antitrust laws -- that's what really counts. For practical purposes, baseball is really no more exempt than the NFL, NBA, airline industry, automobile industry, etc.

As for the territorial discussion, let's consider Subway restaurants. If a Subway franchisee wants to open a restaurant 6 blocks from an existing restaurant owned by a different franchisee, he can't -- because the franchise contract provides for certain territorial limitations, etc. Obviously, some Subway locations are much more lucrative than others. Baseball is really no different -- off the field, teams are part of a single economic entity -- MLB (not the Yankees) is the equivalent of Subway. The Yankees are the equivalent of the New York City Subway franchisee. Is Subway socialist (not capitalist) because they limit the rights of their franchisees to open restaurants in certain geographic locations? Of course not.

The market does not directly determine how many Subway restaurants a certain area supports -- Subway decides that, although the decision is heavily influenced (assuming Subway is smart) by market realities.

Does a Subway restaurant compete with other Subway restaurants? Not really -- or at least not to a significant degree. Subway competes with Quizno's, McDonald's, Burger King, etc. Likewise, the Yankees and the Royals don't really compete economically -- they are part of a larger economic entity (MLB), which competes with other entities for its share of Americans' disposable income (e.g., other major sports leagues, minor-league baseball, the PGA and professional tennis tours, and a number of non-spectator activities -- bowling, movies, etc.)

1. First, doesn't baseball's antitrust exemption prevent franchises from moving wherever they choose, unless they have approval from the league? Al Davis moved the Raiders from Oakland to L.A. and then back to Oakland but pro football is not exempt from antitrust regulation. The fact that owners and players in all the pro sports can agree in their collective bargaining agreement to items like the amateur draft (which absent a CBA would raise antitrust issues) is irrelevant to my point here.

2. Second, major league franchises are not precisely analagous to Subway franchises in a particular geographic area. Such Subway franchises operate independently of each other. Yes, Subway may keep a new franchisee from opening a restaurant next to door to an existing Subway but in terms of operation, they are independent of each other. Same cannot be said for the Yankees and the Royals.

The Yankees can schedule a homestand but they need an opponent to have a game. If the system for distributing local media revenue gives the Yankees the opportunity to spend $200 million/year for revenue but the Royals can only spend $40 million/year, then eventually the Royals will become nothing more than baseball's answer to the Washington Generals.

Actually, the small market teams like K.C., Milwaukee and Cincinnati have more power than they may realize in this situation. What would happen, for example, if the Royals and other small market clubs simply refused to play the Yankees? Without opponents, the Yankees have no games to play. The small market clubs need to play this card to make the Yankees act responsibly. The Yanks -- led by the petutlant, cry-baby Steinbrenner family -- certainly won't do it on their own.

CC has not been quite as injury free as the picture you paint. This is from the Indians web site and was written 3/28/07:

"Indians ace suffers left forearm contusion against Jays

Sabathia is no stranger to injuries this time of year.

He strained his right oblique muscle while warming up in the bullpen for his first exhibition start in 2005 and ended up missing the first two weeks of the regular season. Last year, he left his Opening Day start against the White Sox in the third inning with another oblique injury. That one cost him the remainder of the first month of the season."

Drat, I missed the 2005 oblique injury, for some reason - it was in our database.

The 2006 injury is the one to which I referred as a groin strain. I must have picked that up from a single erroneous source in the midst of a deadline rush (these pieces mirrored on SI.com are written pretty frantically as news breaks), but all of Will Carroll's reporting in UTK says it was an oblique injury as well.

Either way, the point is that he's never had an arm injury that's caused him to miss time the way Burnett has.

Jay, I'm sort of curious. How long do you intend to refer to Chamberlain's injury last year as "season ending"? He returned from his "season ending" injury in September, and made (count 'em) 10 appearances. Just sayin'.

D'oh! E-6. It did end Chamberlain's season as a starter, and it did end the season for me as a Yankee fan, more or less, since I soon stopped rationally hoping they could pull off a comeback and tuning in on a near-nightly basis.

But you're right, Chamberlain did return, albeit as a reliever. You'd think given the three times I've referred to it in articles this month that between my editors at BP and SI and my readers in both spots, someone would have called that to my attention by now.

Nobody's shy about pointing out when they disagree with me on matters of opinion, and I take that in stride; it's part of the job. But if I make a factual error (such as the Sabathia groin/oblique injury) and even worse, repeat it, I'd appreciate somebody who catches that speaking up before I perpetuate it. So thanks for doing just that, seriously.